When 10 year old Katie Blasko goes missing, Ellen Destry is in charge of the case. Katie's from one of the local Estates – a poor, run-down area full of dysfunctional families, violence and drugs. Nearly everybody on the investigation team is pretty sure that Katie's disappearance is yet another family out of control - Katie's either fallen prey to her mother's de facto, she's run away, or any of the other things that happen all too frequently to little kids on the Estate. Ellen Destry's not so sure, she's got this feeling that Katie's been abducted and she's got this nagging concern about rumours that have been flying about a paedophile ring on the Peninsula. She's also more than aware that the powers that be in Waterloo Police Station are not convinced she's up to running an investigation of this type. What makes her really sensitive to their thoughts, is that she's agrees with them.

Hal Challis, however, can't be much help. He's half-way across Australia, in the outback of South Australia, watching his elderly and frail father die. He's also wondering what happened to his brother in law who disappeared a few years before, his car found abandoned in the outback. Hal's sister has always thought he did a runner, after all, she's been receiving strange correspondence which seemed to indicate he was somewhere, alive. Hal's not so sure and, because he can't help himself, he intervenes.

Having read all of Garry Disher's Challis series, CHAIN OF EVIDENCE stands out as the best book thus far – at least for me. There is a deftness in the drawing of the two separate plots, and the characters that gave this book a real focus and tension. The main plot, the possible abduction of the young girl is intricate, complicated and involves the Waterloo Police Station in a number of unexpected ways. The complications of the relationship (or lack of relationship) between Challis and Destry has an extra level of interest because of the physical distance between the two characters. Another element was, what seemed like, a deliberate choice of the types of investigations for both characters – Challis is a dry, sparse, reserved man investigating an old disappearance in a dry, reserved, desert edge town. Destry is a more emotional, complicated, outgoing woman, investigating a messy, complicated and intricate crime in a lusher, familiar environment. In this instance, this didn't resonate as a cliché.

CHAIN OF EVIDENCE flags a strong shift of focus from a series concentrating on Hal Challis, with a touch of Ellen Destry on the side, to a combined focus as both characters take centre stage, albeit in different investigations and in different states. This bodes very well for the ongoing development of this series.